Glow Plug Adapter
 

I finally got a chance to make the glow plug adapters that will let me use standard 240/300D Bosch pencil glow plugs in place of the loop plugs.

I was corresponding with another member and he suggested that I start a thread and post some pictures of them. I was not going to, but these things work so well that I thought what the hell, if someone else has the capability they might get some inspiration.

I made the adapters instead of buying the special pencil plugs because I like use standard parts that I can get anywhere, any time. Plus I did not like how the special plugs did not take up as much volume as the loop plugs do.

I designed the adapter to hold the heating element back a bit, (not sticking in as far as the loop did), to help keep the element from interfering with the swirl. The car starts amazing now and I have noticed that around town the EGTs are about 50*F cooler. It also seems to smoke less and pull a little stronger.

All in all a very worth while project.

ok. are you going to sell these or are you going to publish specs for them?
the pic makes me think the new plugs are not going to sit as deep as they should. also the shield on the glow makes me think the plugs are not going to heat up properly, and could burn out sooner... isn't more than the tip supposed to glow?

A perfect CNC job to run a couple thousand off of

I've given up on selling anything I make, I'm too expensive.

As for publishing the "specks", no for the very points you make below, (Questionable plug life and performance). I designed this part for use in my engine, so I assume all the risks. This is one of the reasons that I was hesitant about a thread on it.

My intension is to post my "perceived" outcome with this approach, so that others that are looking for an alternative to the special, large threaded pencil glow plugs, and, have the ability to design create parts, could have a reference to evaluate and compare to there design.

Yes you are correct. As I stated in the first post, I purposefully placed the tip of the glow plug further out from the center of the prechamber, (not sticking in as far as the end of the loop did), for turbulence reasons. If I had to, I could sink the tapered seat a little deeper. I can't imagine the engine starting any better, so I will not be messing with the depth. I am going to check to see that the tapered seat is indeed sealing properly after a few more miles.

Time will tell on the burning out thought. As far as I know, it is the tip that gets the hottest, that makes sense to me anyway.

That kind of thinking will get you into trouble.

I would bet you a beer that you could not even sell enough for 10 cars over a years time unless you gave them away.

SWEET!
 

Nice machine work. Damn good idea.

Try finding the upgraded 240 pencil plug when you break down in any town USA. The smaller pencil type are readily available. I had looked for an adapter to no avail . I finally resorted to always having a spare in the glove box.

Judging by the markings on the nut you used a old plug body for the foundation of the adapter? Nice set up .


Scratch that looked back at the picture all raw material.

To be honest I'm surprised it's not manufactured already.

The adapter opens up a host of other options including adding a glow system that allows for pre and post glow capability, which all duraterm plugs support.

I do understand your reluctance, I've been burned before in similar circumstances.

Very nice work

Steve A

I am the one who suggested that he start a thread.

I doubt if any of the negatives suggested so far will cause any issues.

If you believe the Factory drawing not much of the Glow Plug sticks out; and if the Glow Plugs are working correctly only the tip gets hot. See thumbnails.

I say an excellent job.

Hears a thought.
With the newer Plugs and I believe you could use a Glow Plug Relay with the After Glow function.

Thanks to all for the complements, I appreciate the positive feedback. I take pride in my work and it is nice to hear that others appreciate it as well.

The reason I posted in the first place was so if someone wants to run with an/this, idea/project, they could and I would be fine with that.

For reference, I would have to get $50.00 per adapter if I made them. That is based on my machine rate of $75.00/hr

I was thinking the same thing, especially if he's using duraterm gp's. Then again it would make the system more complicated.

Steve A

Yes, I believe you are correct. I have a switch that I can use to hold the glow plugs on after starting. The new plugs stay hot longer so I have not had to hold them on.

When it gets cold it might be necessary to hold them though.

Yes, it is more complicated.
I was thinking of those folks who have low compression issues with hard starteing where ounce the Engine is up to temp it runs OK; but ounce they get started the Engine limps along until it is up to temp.

It might allow them to get some more years of use out of the Engine.

What models and tears are equipped with "after glow function"?

....just curious, for future references....:o

I can appreciate creative work-arounds, but is it really that onerous to have to carry a couple of spare retrofit pencil plugs?